| Shaft assembly -> Monitor Keywords |
|
|
 
Shaft assemblyRelated Patent Categories: Rotary Shafts, Gudgeons, Housings, And Flexible Couplings For Rotary Shafts, Torque Transmitted Via Flexible ElementShaft assembly description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070178975, Shaft assembly. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a continuing application, under 35 U.S.C. .sctn. 120, of copending international application PCT/EP2005008975, filed Aug. 19, 2005, which designated the United States; this application also claims the priority, under 35 U.S.C. .sctn. 119, of German patent application DE 10 2004 043 621.5, filed Sep. 7, 2004; the prior applications are herewith incorporated by reference in their entirety. BACKGROUND OF THE INVENTION Field of the Invention [0002] The invention relates to a telescoping shaft assembly with at least two shaft elements capable of sliding in one another. The two elements form an internal shaft element on the one hand and an outer shaft element on the other hand, and they are connected to one another in torque transmitting manner via at least one sliding splined portion. An axial fixation is provided in the manner of a predetermined breaking point between the shaft elements. The axial fixation becomes ineffective once a predetermined impact force acting in the direction of telescoping is reached. The shaft elements are movable relative to one another, once the axial fixation has become ineffective, in low-friction manner along the sliding splined portion under the action of the impact force. [0003] Shaft assemblies of the generic type are described, for example, in U.S. Pat. Nos. 6,279,221 and 6,193,612. In this connection, reference is also had to a publication entitled "slip-in-tube universal-joint shaft" technology (12th Aachen Colloquium "Automobile and Engine Technology", 2003, pp. 1485-95). One object of the shaft assembly described therein is to optimize collapse behavior in the event of a crash. To this end, it is proposed that, in the event of telescoping due to an accident, impact energy is at least partially absorbed by purposeful deformation. This is achieved, for example, by an inner shaft element being driven out of the splined portion into a tapered zone of an outer shaft element. Movement into the tapered zone brings about forced deformation of the inner shaft element, which ultimately results in the fragmentation of the end region of the inner shaft element. SUMMARY OF THE INVENTION [0004] It is accordingly an object of the invention to provide a shaft assembly, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides for a shaft assembly by way of which it is possible, in particular for all-wheel drive vehicles, to reduce the loads to which occupants are exposed in frontal-impact accidents. [0005] With the foregoing and other objects in view there is provided, in accordance with the invention, a telescopable shaft assembly, comprising: at least two shaft elements capable of sliding in one another, the shaft elements including an internal shaft element and an outer shaft element; at least one sliding splined portion connecting the two shaft elements to one another in a torque transmitting manner; an axial fixation forming a predetermined breaking point between the shaft elements, the axial fixation becoming ineffective once a predetermined impact force acting in a telescoping direction is reached; the shaft elements being movable relative to one another, once the axial fixation has become ineffective, in low-friction manner along the sliding splined portion under action of the impact force; the outer shaft element having a free end formed with a splined portion runout and the inner shaft element is formed with an unsplined portion; wherein, when the axial fixation is effective, an annular gap is formed between the splined portion runout on the outer shaft element and the unsplined portion of the inner shaft element; and a sealant at least partially filling the annular gap, at least in an area of the free end of the outer shaft element. [0006] In contrast with the previous design philosophy with purposeful energy absorption during collapse of the telescopable shaft elements under crash conditions, it is now proposed according to the invention that an axial fixation designed for normal operation of the vehicle be provided, which fixation becomes ineffective in the event of a vehicle accident, thus for example fractures, tears, shears or the like, once a predetermined impact force is reached. Once this axial fixation configured in the manner of a predetermined breaking point has become ineffective, it no longer prevents the shaft elements from telescoping into one another, but instead permits low-friction telescoping of the shaft elements under the action of the impact force. A typical order of magnitude for design of the axial fixation may be a limit force of for example 5 to 40 kN (kilonewtons). If, in the event of a crash, the impact force reaches this predetermined limit force, the axial fixation is nullified and the impact force is thus opposed by a lower resistance. [0007] The term "low-friction" as used herein is to be understood to mean that even forces of less than 50% to 10% of the designed limit force for the axial fixation are sufficient to move the shaft elements relative to one another. [0008] A shaft assembly designed in this manner, in particular for a front cardan shaft (i.e., propshaft) in an all-wheel drive vehicle with a transverse, front-mounted engine, is advantageous because dispensing with deformation in the shaft assembly does not give rise to any hazard due to components snapping or breaking away. Any intrusion of such components into the passenger compartment is thus reliably avoided. [0009] The axial fixation itself may preferably also be used at the same time to ensure exact alignment of the shaft axes with one another. Advantageously, such exact alignment is achieved, for example, by press fitting between the tooth tip and tooth root in the splined portion of at least one of the two shaft elements. [0010] In order to increase the service life of shaft assemblies according to the invention, it is moreover provided that a seal is inserted into an annular gap arising between the shaft elements, which seal may, for example, assume the form of a sealing ring or a formless sealant of the paste or gel type. The sealant itself may take the form of an adhesive, which thus simultaneously assumes the axial fixation function. Additionally or alternatively, axial fixation may also be provided by an insert which may be fitted between the two shaft elements, the insert likewise preferably being associated with a sealing element. [0011] To ensure an extended life of the entire shaft assembly, the splined portion is preferably introduced by cold forming, for example cold rolling. [0012] In accordance with an added feature of the invention, the axial fixation is formed by an adhesive bond and/or weld and/or calking and/or a combination of shear elements and/or frictional portions in the sliding splined portion and/or the like. [0013] In accordance with an additional feature of the invention, the annular gap is sealed by the sealant. In accordance with an additional feature of the invention, the sealant is a sealing ring or a formless sealant of the sealing cord, paste or gel type. Continue reading about Shaft assembly... Full patent description for Shaft assembly Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Shaft assembly patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Shaft assembly or other areas of interest. ### Previous Patent Application: Timing offset tolerant karaoke game Next Patent Application: Balance assembly for coupling first and second rotating members Industry Class: Rotary shafts, gudgeons, housings, and flexible couplings for rotary shafts ### FreshPatents.com Support Thank you for viewing the Shaft assembly patent info. IP-related news and info Results in 0.12758 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
